San Diego County building permit activity improved in June, outpacing some other metro areas in the state, the Construction Industry Research Board reported Monday.

Housing unit permits stood at 384, up from 225 in May but down from 559 in June 2010. For the year to date, permits in San Diego were up 38.5 percent from the same period last year, compared with a gain of 5.7 percent for the state.

In nonresidential activity, local valuations were up 49.9 percent to $1.3 billion for the January-June period, compared with a 11.8 percent rise for the entire state.

University of San Diego economist Alan Gin said the trends are not encouraging, given that apartment building activity started strong at the beginning of the year and trailed off lately.

"What's particularly significant is June is usually the best month of the year for building permits," Gin said. "Typically it's about 30 percent more than the average month."

With the recent monthly average at 500 housing units, June was 23.2 percent below average. If it hewed to historic trends, the total should have been 650 units, not 384.

Gin said he would wait until he sees the July and perhaps August unit count before he decides if residential building is going into another downturn.

"What we need to see is whether the last two months were aberrations or not," he said.

In the noncommercial categories, the research board reported strong upturns in office, retail and hotels, compared with 2010 levels at this time. The total for the first six months exceeds all of 2010, $594.9 million so far this year, compared with $307.3 million for the entire last year.

"Maybe there's some optimism on the commercial side, despite the fact you keep hearing vacancies are pretty high and that retailing is under pressure," Gin said.

He said what may explain the upsurge is the very low amount of nonresidential building activity in 2009 and 2010, so that 2011 looks quite strong by comparison.

"Even if there is an improvement, it still leaves us in a pretty bad spot," he said. "It's still bad, less bad than we were, but still not great."

He said future nonresidential building depends on broad economic conditions and then it becomes a chicken-and-egg conundrum: Consumers are not spending because businesses aren't hiring and they're not hiring because consumers aren't spending. The result is less hiring and less real estate demand.

San Diego may be doing better than other parts of the state, he said, because it entered the recession before many other areas and should emerge earlier.

"Things are flattening out at least in the last couple months," he said. "The big question right now is, will that continue? If it continues, that could take us into a double-dip situation."

Gin pays particular attention to building permits because they represent a key factor in his monthly leading economic indicator reports.

"They suggest future activity," he said. "There is the suggestion that builders bet with their money. So we are a little concerned here."

A separate report toted up public works and heavy construction in June.

It showed that school and community college building activity was up 57.3 percent to $180.6 million for the first six months of the year, while other government building projects were down 23.2 percent to $104.3 million for a total $284.9 million, 13.6 percent ahead of year-ago levels. Statewide, the public building sector was down 16.7 percent over the esame period to $3.2 billion.

In heavy construction of civil engineering public works, SAn Diego was up 140.7 percent to $152 million for roads and bridges but down 64.9 percent to $151 million for other infrastructure, such as sewer and water works. The overall total was $493.4 million, down 38.6 percent from year-ago levels. Statewide, the total in this category was up 18 percent to $4.8 billion.